1. Field of the Invention
The present invention relates to a motor control method and system, which determine a failure of Hall sensors in a motor and control the motor even when a failure occurs in some of the Hall sensors.
2. Description of the Related Art
A typical 3-phase motor includes a 3-phase coil installed on a stator and a permanent magnet magnetized on a rotor. A driving circuit for the 3-phase motor causes current to flow through respective phases of coils on the stator, and the rotor of the motor is rotated by a magnetic field based on the current supplied from the driving circuit. To continuously rotate the rotor of the motor in one direction, the position of the rotor must be detected, and switching elements for switching the directions of currents flowing through the respective phases of the coils must be sequentially turned on and off based on the detected position of the rotor.
In particular, the accurate position of the rotor is detected using three Hall signals, which are formed by the magnetic field of the rotor and have a phase difference of 120°. The three Hall signals are detected by Hall detectors such as Hall sensors or Hall Integrated Circuits (ICs). Therefore, the motor and the driving circuit thereof are driven or operated when the position information of the rotor is obtained from the Hall sensors. However, such Hall sensors are known to easily break down and also vary due to external factors, such as temperature, thus resulting in the malfunction of the motor.
Therefore, as a fault diagnosis control method for preventing the malfunction of a motor has been developed in the related art and includes analyzing eigenvalues using a Minimum Description Length (MDL) technique and utilizing the number of signal eigenvalues having magnitudes greater than those of noise eigenvalues as a new fault index, thus perfectly performing fault diagnosis. However, since this method cannot detect faults even in the Hall sensors disposed within the motor, the above problem still remains without being solved.
The foregoing is intended merely to aid in the better understanding of the background of the present invention, and is not intended to mean that the present invention falls within the purview of the related art that is already known to those skilled in the art.